Pneumatic seed meters are well known in the art. There are two basic types of pneumatic seed meters, positive air pressure seed meters and vacuum seed meters. Both of these types of pneumatic seed meters have a rotatable disc located in a housing. The rotatable disc is provided with circumferentially spaced apertures defining seed locations. The rotatable disc is rotated through a seed puddle and the individual seeds are attracted to the spaced apertures by the difference in pneumatic pressure on one side of the disc from the other. The individual seeds are then taken up by the disc and rotated to an outlet where the differential pneumatic pressure is removed and the seed is deposited into a seed tube for travel to a planting furrow.
In a positive pressure seed meter the difference in pneumatic pressure is created from a positive pressure source. The seed puddle, in a positive pressure seed meter, is located on the same side of the disc as source of positive pneumatic air pressure. In a vacuum seed meter the difference in pneumatic pressure is created by negative air pressure. The seed puddle, in a vacuum seed meter, is located on the opposite side of the disc from the source of negative pneumatic pressure.
Row crop planters are typically provided with a plurality of planting units. Each of the planting units have a seed meter. Sometimes it is desirable to disable a number of the planting units while still planting. For example every other planting unit may be disabled, so that the row crop planter can plant thirty inch row corn instead of fifteen inch row soybeans. First the planting unit is lifted off the ground and locked in place. With pneumatic pressure seed meters it is also necessary to close off the pneumatic pressure source. One solution is to remove the pneumatic hose supplying pneumatic pressure to the seed meter from a pneumatic manifold. The pneumatic hose opening in the manifold is then closed off with a rubber cap. This operation can prove difficult as the manifold can be difficult to get to. In addition, the pneumatic hose is left free to hang leaving it susceptible to damage.